The long term goal of this research is to determine how odorant information is processed in the vertebrate olfactory system. Olfactory brain areas are sites of several human pathologies, including epilepsy and Alzheimer's disease. Olfaction is important in many species for such diverse activities as food finding, reproduction, and inter-species communication. The olfactory system supports this diversity by functioning as a highly sensitive molecular detector capable of discriminating among large numbers of odorant. Although the olfactory system has rather well-defined anatomy and physiology, much is unknown about how it functions, despite its basic neurobiological and clinical relevance. The specific aim of these studies is to test the hypothesis that patterns of neuronal activity in the olfactory epithelium and bulb are related to one or more defined chemical attributes of an odorant stimulus molecule. This hypothesis will be tested by I) recording spatial and temporal patterns of odorant-elicited activity in the salamander olfactory system by video imaging of voltage-sensitive dye fluorescence, and 2) comparing these patterns of neuronal activity with the physical chemical properties of the odorant molecule.